JP2005-224008A discloses a rotating electrical machine system that integrally includes an electrical motor as a rotating electrical machine and an inverter device that converts direct current into alternating current to supply to this electrical motor.
In this rotating electrical machine system, cooling passages for cooling a stator of the motor are disposed in a housing that houses the motor, a cooler for cooling a semiconductor module of the inverter device is installed on the housing in a state housed in an enclosure. The cooler is coupled to upstream-side and downstream-side cooling passages. Cooling water supplied from the upstream-side cooling passage to the cooler passes through an inside of the cooler to be discharged to the downstream-side cooling passage.